Tractor-borne implement



July 22, 1952 v, HANSEN 2,604,027

' TRACTOR-BORNE IMPLEMENT Filed Aug. 24, 1945 4 Sheets- Sheet 1 July 22, 1952 H. v. HANSEN TRACTOR-BORNE IMPLEMENT 4 Sheets-Sheet 2 Filed Aug. 24, 1945 NVBN'TOM QJa rolol V Homse l 6 J J (jg ITO ajyJ y 22, 1952 H. v. HANSEN TRACTOR-BORNE IMPLEMENT Filed Aug. 24, 1945 4 Sheet-Sheet 3 -faroid V q-(qnsen y 22, 1952 H. v. HANSEN TRACTOR-BORNE IMPLEMEII'I.

4 Sheets-Sheet 4 Filed Aug. 24, 1945 Harold VQ-(anseri Patented July 22, 1952 y: 'L

arms, together with th the present suflice it to note that a pair of latare suspended by drop links I! from correspond ing crank arms I8 fixed to the opposite ends ofi.

a transverse rock shaft l9 which is arranged to.

be turned by a hydraulic ram (not shown In general the arrangement is such that upon ad- 10 mission of hydraulic fluid to the ram the links H are raised to the dotted line position shown in ,ZAlso trailing from the tractor is a top link 23.

(Fig.4) pivoted'at 2| on a shackle 22. As disclosed in Ferguson Patent No. 2,118,180 referred to above, the thrust on the top link, resisted by ..'a spring 23, may be 'utilized to control the hyfjdraulic systemautomatically in regulating the draft load of a tillage implement or the like. In

the present implement. however, the hydraulic system is used primarily simply for raising and lowering the implement between transport and working positions, so no further note of the potentially available automatic control need be taken here. v general, thepresently disclosed implement isso, constructed that when raised to the trans- .port position shown in Fig.1, both of the marker arms H are automatically located in their raised or. transport, positions also'there shown. shifting a selector or control rod 24 the operator preliminarily conditions one or the other of .the marker arms forv automatic lowering into lworking position .as an incident to subsequent.

, 1..Iurning now to somewhat more of the detail" f of theillustrated implement, the main frame I!) I is ofinverted T-shape (Fig. 1). It includes a 'horizontaltubular beam 25 of diamond-shaped cross section (see Fig. 9 for cross section), as; V 50 "wellas'a pair of uprights 2 6 rigidly fixed to the central portion of the beam25 injclosely spaced relation to each other. Brackets 21 fixed to the ".beam.25 are pivotally connected at their upper Tends to the trailing ends of the tractor-bornev the quadrilateral linkage noted is utilized in I actuating the marker arms l i, ina manner which will later appear, h I

To the outer ends of the frame beam 25 are .pivoted the marker arms II to swing vertically about horizontal axes extending longitudinally -of the path-of tractor travel. For that purpose generally triangular gusset plates are fixed at their apexe'sto'opposite ends of the beam 25 and have rock shafts 3| mounted to extend along their lower portions and on which the marker arms are pivoted. On the outer ends of the marker arms are brackets 33 on which are r0- tatably journaled marker disks 34.

Joining the marker arms H is a flexible line shown as a chain 35. Thisflchain is short enough that only one ma'rker "arm at a'time' can be located in horizontal or lowered position. When one. arm is so loweredjthe other mustfbein raised position. Itis by appropriately tensioning this chain and byslacking ofl a portion offit while clamping another portio'n'that the marker arms vare manipulated. It will be noted that the chain is led'over'idler or guide sheaves 36 .journaled at opposite ends of thebeam 25 (Fig. l) ,and j thence over a, second pair *of guide 'sh eaves 31, 38 (Figs. 6 and 10) journaled adjacent thejbeam to rotate about spaced vertical axes. The portion Ofth chain running between the last-mentioned1pair"of sheaves is. trained over a central sheave :39 which 'i's movable bodily ;,t.0W,ar.d and from the pair 31,, 38.'. j "I To apply tension to the" chain and thus draw a'bight initsicentral portion toplace the marker arms H in their transport position" shown in .li'ig,."l, the central sheave 39 is pulled forward to the position diagrammed in Fig; 6. The linkage arrangement for effecting suchbodily shift of [the sheave 39 will be described below. Alternately engageable locking dogs 40, Marc provided for clamping the opposed portions of the chain against corresponding ones of the pair ofsheaves 31, 38. 'Such dogsare moved alternatelyjinto and out of locking positions by the I manual selector 24; When the left hand dog 40 .is in locking position and the righthand dog released, as shown in Fig. 7, lowering of the righthand marker arm vll to the position of Fig.

. 2ensues upon a rearward movement of the cen- ;tension or draft links 114, thus suspendingthe implement from such links. 'Ihe rear end of -the. top link 20 (see Fig. 4) is received between jandfpivotally connected to the uprights 26 by a .di'sjengageable universal ball joint 28 (Figs. 1

if.andf5)l g 0n theiframe beam 25 may be mounted suit- "able planter unitsP indicated in broken lines. Since various forms of such units are well known, and in any event form no part ofthe present invention, detailing appears to be unnecessary.

Upon reference to Fig. 4, it will be perceived ,that the frame l0 joins the upper andlower draft links 20, to complete a jointed quadrilateral figure, ofwhich the front side is constituted by:

the diiferential housing 29 ofthe,tractor.; It will lbe further notedftha't such quadrilateral figure is "partially collapsed npon raising of the; implement to transport positionand is distended upon tral sheave 39 to slack off ,the bightinthe, chain 35." Similarly. whe'nthe righthand dog 4|.fis engaged and the lefthand dog released as-in Fig. .18, lowering of'the lefthandmarkerl arm tothe position of Fig. 3' takes place 'upon rearward movement of the central sheave 39 to slack off .the'chain. In each-case the marker? arm corresponding to the locked'dogremainsfin elevated position; Should. both: dogs be in locking 0! clamping position, both arms remain elevated" as the chain is slackened. Detail of the chain locking mechanism including the locking dogs lfl,v 41 appears in Figs. 9 and 10. As there shown,.the dogs are eccentrically journaled on pivot pins 42 rigid with and extending upwardly from a horizontal supportlowering to the working position shown'in full; e np by Such means as cotter-pins lines. Such alternate collapse and distention of (not shown) through the upper ends of the pivot rite pine. eccentric eurreeeser the hog have Toughened or -sha110W1y"tooth'ed" surfaces 45 thereon arraneeito be'mov'ed toward theeis'sm eieted'sheav'es 3-l'; -38'-'as the dogs 40, 4l-1. are refspetively swung counterclockwise and clockwe-e: Contractile 'spri'ngs 46 anchored to az pin 4 zit-tending between the plates 43; 44endfto resp'eetive ones of 'the dogs 40; 4| 'i i rge the latter 'y-i'el dabl'y toward locking position. A-"eoactihg T- shapedi hlo'ekih'gem 48 serves 'to'cem alternate ones 'of the dog's "into v released} bosi-tidn, While *rreeing the remaining dog formovement 'iiito engaged 'position it's biasing" spri ng. the fslhe-ped *ca'm isffixed to a pin 49 oscillatably 'l moiihted inf-the supporting plates E43, 4-4 and with the arms of the T eispesed -'no"enge e -'eeri respondinghrojeotions 40a; 411 on theglogs' 40, 4 An; over 'oenter"s'pring 50" anchoretito/tfhe .7 5. pd bf we te n P t 'T- ei? j =a 14' 92nd tothe stationery pin 41'serves to sr'itpj'the earn from dead center positiori 'viiheh thelatter is "m'o'i'egi by the manual selector rod 24.

- hsto "the selector 'rod' 24, it willb e seived "epori referehce tolfig; that it *is slidai'bly guided "for Eetidwise movement in a bracket 51*se01'1'red to t me topflin-k 29; The bracket 5 l" and the upp r hdof the rod 24 may; for example, be provided "with eppropriete' notch and detent meehajm'sm to define anextreme forward, an extreme. rearward, Ie'fid a ceptraI position for the selector rod 24. f'I'he' lower end'ofthe rod is pivotally' connected ah;;arm" 52"('Figs; 5 and 9) projecting literally the pin '49 to which the T-shapeq 'eer'nj 4'8 red 24 mm its irorwa position, the *r-s 'aped foam isrock'ed in the} opposite, or eloekwise direcii'tojtheposition fsho'wn'in' Fig. '10-, nrimfihg the "other dog "40 to" its 'rele's'ed position, while the dog 4| snaps into locking position. .When

the selector rod is in its central 'p'esmen, it holds- 'j the 'c'em 48 centered, thereby leaving both 'dogs 19 le mng-positien; In other 'wo'rds," when the "T shaped; cam. 48"is in Central position both of firojeetionslifla, '4la are freed by it so that the eoh'tractileosprihgs '46 pull 'both of, the dogs 40f 41 into 1'o 'c'king position. thus locking o th dogs 'bbth of the marker arms may 'be locked in elevated transport 'Dosi't'ioh.

ttention my next beqgive tothe arrangean::i n' ry linkege (Fig. 41 is errengee tolbe fectuetez'ijjhyi the main: -1mke'ge' rer thet purpose.

x Y 91510; moving the central sheaves f39 into and o titjfo'f "chain 'tefisi'ohing' position. As heretofore mehtiohe'd, the bodily movemeht of the sheajve f gflforterrsionin'g and slacking off? the chain 351s a1 jinirrplished as an ine'id'e'nt to raising ahd 1ow 1 ring ;o1 ;the-tr'aetor-berne 'dreftnhkege "I4,

A j r I H djalgenerally up i ht 1ihk 55 extendin'g" alon 'the 'forwlrd' side time fremeii ghtsny enwts erepivqted 'dogeth 'r'e 56' for ward endofthe up'pjer link "5 ".toiriihk; ZO'b'y' 'pijn "511i'1erted 1 -the; toeqmk, w ereas theothei' fiery 'i'ixili'ss .JSjiIVoted at ES intermediateits'entl ,isa extending rerwardly fram 6 45 e re'swune Hack to' th'e full linepo'sitio shown "in 'aoL As the ma ingdrart iihlg 'a'ge- 4', 20* wring-" e w w r'llifti'rrg' the im men-t :to trafisport posi iqentauyiwi'ththe approee ot the mime towaird the tep 'link 'fl w takes p be "do hg th-iis'oofl'eps'i-ng movemen' the auxii 'e -i in s 'sa, we il'sp ee lep'sea e'r'eeiseered teward each othe I The resultant thrust of the ti ee euxh iery" nk Men the vertical euxniery 'lfniifiifi'ocks the letterebout it's-Divot 59-. -It'wm be'jereei vea memo-e the upper link 54 eoniieets'the up t- 11111555 to the tractor Cthrou'gh the top link 2m et a 'oint-e z'e'entric toi pivot's' 'fli) for the lower draft links 14 that the'l-ihk 55 fwi1l be roekegi'fore and aft as an 'in'oide'nt to raising emilowering of bhe qlmks '14-. To anaryze "the linkag motion in" a somewhat-different manner, be observedthat the topdr'aft link 20 sipd ff e' upri'ghts "'ns'titute'the arms: of 'a 'firs't seesaw 23nd the {ax-1: liar-y links 54; 55- constitute thearms 0f ja 'se'eon d scissors and; Whih ro'iighLy perell'e'ls "the first. "Lethe pivot between 20 a'nd (28 were odi'heidfen t with thepivot betwe'e'n 54 and 55 then-there wo'iild be norelative "mhveme'nt b'etween aliena- 54' nor between 26 ahd"55-. -But;

if! t e-engmar mefionef the uxnie A reference teea'e other; Mereever it is noted-"thattheterther the free 'ender'me ink will be t e length movement-0T such free end e w t "in 'a n'gle of the linksi' t, 55' relative to ach other.

h reference to the frame for any n -charig'e -As lower en or the 1i-nk'55 is swu g forwerd it draw's the sheave 39 fdrwar'd'withit." "Similarly, as the 'imol'e'ment "is: loweredby the draft linkage back" into WOIKiIl-Q-fidsitibh, the auxiliary; H'nk's Figi'4; Thejwei'ght'of the freed one-of the marker "arms 11" keeps the imlocked portion-of the' ehain '35 tzut at all tir'ne's as the central 's'he'ave '39 reeve rearwerdly. Whenthe marker arms are fiilly 'upright theyer'e nearly bala'hefd, To afford an initial imp ilse of-fo'rce for lowering the arms.

springs 32 loosely-surround thee'nd portion! the ehem bet-Ween the guide sheaves 36- an i the fmfar lier arm s. These sp'rmgsjwiH be compressed by the marker arms against the supports for the guide sheafves 36 when the arms are upright.

one 10f the errhs; the corresponding "sprihgs 32 i rew q t u e d nt" a miqu wa lend; thus 'imtiate; its descent. Thereafter the weight-er the. arm holds the 'cheii'r taut.

3 11 55 as it-swirigsr erwaraand thus "Iimitsueh er lbweri g movement or thefdieift linkeifge i a whole. The point of connection of'th'elii e h'the't the ele fien or the draft linka'gel'a'hd h'eneeof the 'im pl'e'irnent "fromt h'e greun' "hen in lowered position, is at e qesireci level for rop'er ground engagement by'the markers. "Th'eux- .iiliary linkage .54,- 55 thus-serves; as a, lim ting means in addition to its,;action in the, operation of themarker arms II. ,I' ii; 1 j, a Tors-upp rt t e i plem nt; henitis de ach d from the' tractor, or while it; is being detached, a standifiri (.Fis. ;i.s: pr ided- .Such a d cludes a base plate 64 fixed to an upright stem :or sh nk '55. slidably. received in: a p ure 6 i a. bra ket-1:6 fix o; t e up hts 2,6. ,NQ m Hy the stand is held-elevated in the positionpfaEig. 9 by apin 68 passed through the stem ,65. v The rightangle end of pin 58 falls in a hole in plate 61. to lockpin 68in place. Tolower the stand, it is first raised slightlyuntil the right angle end 'Qfthe pin 68 clears the hole in plate Gland then the, pin is withdrawn; the stand dropped down, ;-and the pinpassed through asecond hole (not shown) higher up in thestem and with beneath the-bracket 61. j The operation of-the disclosed implement will in general be clear fromthe foregoing; Byway of brief recapitulation, let it be'assumed first of all, that the tractor isproceeding with theim- 'plement in the raised-or transport position shown in Fig. ,1. To. start the-planting the operator.

the markerdisks 34 rollsalong the ground in the gusualmanner, leaving amark in the field which serves as a guide for the tractor driver in planting ,the-next row As each row is planted a mark is made with the appropriate one of the markers for accurate guiding during theplanting of a succeeding rowa Planting in precisely spaced rowsis thus made feasible. The operator has, at all times, full manual control of the marker arms. Upon approaching an obstruction hey can raise the implement,.cau sing the lowered marker arm .to rise. Upon again'lowering the implement that same marker armwill drop again into working position if he has not shifted the controlrod zfl.

should he wish to alternatethe marker arm po-- sitions he raises theimplement by the hydraulic actuator, and shifts the rod to lock the arm w ic wa -p ev ous low redand free the-other. Thenthe implement is lowered again. I

i To detach the implement from the tractor the stand;63 '(Fig. 9) is lowered and the draft linkage 4, 20, also lowered. Preliminary to suchlowere mg bothof thedogs 40, 4| may be locked by' cntering the releasing cam 48 so that both marker arms ll will be retained in elevated position 4' as theirnplement islowered. With the imple- 'ment resting on its supporting stand 63 and planterfunit ground wheels it'is but the work of a'moment to disengage the pivotal connections of the brackets 21 with the lower links M'arid'the pivotalconnection' 2| of the upper link with the shackle 22. Having disengaged these three'connections the tractor can be driven away and another implement attached if desired. Reatta'chmentof the present implement is obviously equaliyslmple. 7 ,1, I claim as myinvention;

l; Inan implementfor a tractorhaving a pow,- er lift device thereon, the combination of an implement frame having. means thereon for suspending; said frame from said lift device for bodr ily lifting and lowering movement betweenalter- .nate transportand working positions, a pair of marker arms pivoted on said frame atopposite sides of th'e latter to swing individually between .lowered laterally projecting positions I and up- ,right positions therefor, a flexible line fixed; at its opposite ends to said arms, means operable auto- ,matically as an incident to raising said frame int transport position' b'y thepower lift device. for drawing a bight; in the central portion 'of said line to raise both of said arms to upright position and for slacking off said;bightas an incidentto lowering of said frame, and mean's for clamping said line at points intermediate s'aidbight and individual ones'of said armsto retain the corresponding arms elevatedupo'n slacking off of said bight'by lowering ofsaid frame.

' 2. In an implement for a tractor having apoliter lift device thereon, the combinationof aniin plement frame having means thereon for suspending said' framefromsaidlift device for bodily lifting and lowering movement b'etweenlalt'en.

nate transport and working. positions, a pair of marker arms pivoted on said frame at opposite sides 'of the latter to swingindividually between lowered laterally projecting positions and up.-

right positions therefor, a flexible lin fixed at its opposite ends to said arms, meansoperable automatically as an'incident to raising of said "frame" into transport position by the powerlift device for drawing. a bight in the central portion of said line. to rais'e'both of saidarmstoupright position and forlslacking off said bight as an in- ;cident; to lowering of said framaka pair of clampin'g means for grip-ping said line .at points be- Dowerlift device.

' 3; In'an implement for a tractor h-avingia power lift device thereon, the vcombination of an implement frame having means thereon forsuspending said frame from said lift device for bodily lifting and lowering movement between. jalternate transport and working positions,,alpai1fof marker'arms pivoted on saidlframe'at opposite sides of the latter ,to swing vertically .betwe'n lowered laterally projecting positions andupright positions therefor, a flexible line fixed at 'its op- ;posite'ends-to said arms, a pair of laterally spaced guides on said frameover which said line is .led,

means operable automatically as an incident to raising said frame into transport position "bythe power lift device for drawing a bight in the portion of said line between said guides toraise both of said arms to upright. position and for, slacking off said b ight as an incident to lowering of-said frame and manually operable means for clampmg said line against either-orbothof said guides. 4. In an implement fora tractor having a link jtrailingly pivoted thereon generally horizontally for vertieal swing and also a power liftdevice for ra sing an. implement, 7 the combination ofsan mplement frame, means .pivotally connecting said frame to said link in generallyupright posi- ,tion for scissoring of the two toward andfroin each other as an incident-to rise andfall ofr. the

link and frame, a pair of auxiliary-links extendng respectively along the first-mentioned" link "andv said frame, ,means pivotally connecting respective ones; ofsaid auxiliary links to thefirstmentioned link and to said frame, means pivotally connecting said auxiliary links together but at'a. point offset with respect to the pivotal conncetion. between said frame and the first-mentioned link for effecting scissoring of said auxiliary links in unison with like motion of said frame and said first-mentioned link but throughan exaggerated angle as. compared to the angle of relative-movement. between said frame and said first-mentioned link, an element positionally adlustable withreference to said frame, and means for shiftingsaid element in response to movement of: the one of; said auxiliary links pivoted on said frame. r

5. In an implement for a tractor assembly including a tractor having a vertically swingable draft link trailingly pivoted thereon as well as a power liftdevice for effecting vertical movement of such link, the combination of an implement frame having meansthereon for detachably connecting the same to the draft link for vertical movement of the frame by such link, a pair of marker arms pivoted on said frame at opposite sides of the latter to swing vertically between lowered laterally projecting positions and upright positions therefor, a flexible line fixed at its opposite ends to said arms, means including an auxiliary link pivoted on said frame to rock generally fore and aft of the latter for drawing a bight-in the central portion of said line, and means for connecting said auxiliary link to the tractor assembly at a point eccentric with respect to the axis of vertical swing of the draft link for rocking said auxiliary link as an incident to raising and lowering of the frame by the draft link.

6.- In an implement for a tractor having upper and lower vertically swingable links trailingly pivoted thereon as well as a power lift device for effecting vertical movement of at least one of such links, the combination of an implement frame having means thereon for pivotally connecting the same at respective vertically spaced points t'o'both the upper and lower links, a pair of marker arms pivoted on said frame at opposite sides ofthe latter to swing individually between lowered laterally projecting positions and upright positions therefor, agenerally upright first auxiliary link pivoted intermediate its endson said franidtorock generally "foreand aft of the latter aboutahorizontal axis,"a second auxiliary link pivotally connected to the upper end of the first auxiliary link and adapted to extend forwardly beneath the aforesaid upper link, means pivotally connecting the forward end of said second auxiliary link to the aforesaid upper link for causing said second auxiliary link to rock the upper end of said first auxiliary link rearward upon raising of the aforesaid upper and lower links, and selectively operable means for shifting individual ones of said marker arms in response to rocking of said first auxiliary link.

7. In an implement for a tractor having upper and lower vertically swingable links trailingly pivoted thereon as well as a power lift device for effecting vertical movement of at least one of such links, the combination of an implement frame having means thereon for pivotally connecting the same at respective vertically spaced points to both the upper and lower links, a generally upright first auxiliary link pivoted intermediate its ends on said frame to rock generally fore and aft of the latter about a horizontal axis, a second auxiliary link pivotally connected to the upper end of the first auxiliary link and adapted to extend forwardly beneath. the aforesaid upper link, means pivotally connecting the forward end of said second auxiliary link to the aforesaid upper link for causing said second auxiliary link to rock the upper end of saidfirst auxiliary link rearwardupon raising of the aforesaid upper and lower links, an elementpositionally adjustable with reference to said frame, andmeans, for shifting said element in response to rocking of said first auxiliary link. e

8. In an implement for a tractor having a link trailingly pivoted thereon for vertical movement and also a power lift device, the combina: tion of an implement frame, means pivotally connecting said frame to the link forsciss'oring of the two toward and. from each otheras an incident to rise and fall of the link mad e,- an auxiliary linkage including: a pair of; links pivoted together to swing toward and. from each other, means pivotally connecting respective ones of said auxiliary links to the first-mentioned and to said frame for effecting scissoringof said auxiliary links toward and from each other in unison with likemovement of said frame and said first-mentioned link, thepoint of pivotal connectionof said auxiliary links-to eaclrother being offset with respect to the point of pivotal connection of frame andsaid first-mentioned link, wherefore each of said auxiliary links. moves relative -to its associated one of the latter-elements" in course of the scissoring, and stop means for positively limiting the movement of the auxiliary link pivoted on said frame toward the latter; to correspondingly limit the lowering movement of said frame. i i

9. In an implement for a tractor having-a power actuated lift device thereon, the combination of animplement framehaving means thereon: for suspending said frame from the lift device for bodily lifting and lowering movement betweenalternate transport and working positions, a pair of ground-engaging elements mounted on said frame for individual movement between raised andlowered positions with reference toisaid; frame, and means operable automatically'as: an incident toeachraising of said frametetra-11s.-v port position for effecting the positioning of both of said elements in elevated position, with" refer-r ence to said frame and; operable asan incident; to lowering of said frame for coincidentally lowers ing a selected oneofsaid elements with reference to said frame while, retaining; theiother "element in its elevated position with reference to said frame, said last-mentioned means including a pair of rigid auxiliaryv links pivotally connected to each other, one of said links being pivoted on said frame and the other of said links being pivotally interconnected with the tractor.

10. In an implement for a tractor having a power actuated lift device thereon, the combination of an implement frame having means thereon for suspending said frame from the lift device for bodily lifting and lowering movement between alternate transport and working positions, a pair of ground-engaging elements mounted on said frame for individual movement between raised and lowered positions with reference to said frame, means including a manually operable selector device carried by said frame for looking a selected one of said elements in raised position while leaving the other free to move between a fully raised and a fully lowered position relative to said frame, and means operable automatically as an incident to each raising of said as to smite position for erecting an elevation ,of the freeon e' of said elements and also selector device carried by said. frame having an operative position wherein both of said elements are locked in raised position, said selector device also having additional operative positions wherein respective ones of said elements alone may be locked in raised position while leaving the other free to move up and down, and means operable automatically as an incident to each raising of saidframe to: transport position for effecting an elevation of the free one, if any, of said elements and also operable as an incident to lowering of said frame for'lowering the free one,-if any, of

,said'elments with reference to'said frame.

12'. In an implement for a; tractor having a power actuated lift device thereon, the combination of an implement frame having means thereon for suspending said frame from the lift devicefor bodily lifting and lowering movement between alternate transport and working positions, a pair of ground-engaging elements mounted on said frame forindividual movement between raised and lowered positions with reference to said frame, means including a manually actuatable selector device carried by said frame for locking a-selected one of'said elements in raised position with respect to said frame while leaving the other free" to move up and down throughout successive raising and lowering of said frame and until said selector deviceis manually shifted to a different position 'and means operable automatically as an incident to each raising of said frame to transport'position for effecting an elevation of the free one of said'elements and also operable as anincidentto lowering of said frame for lowering the free one of said elements with'reference to said framef I, i ,7 V 13. In animplement for a tractor having verticallyswingable' upper and lower draft links 12 trailingly pivoted on its rear end portion as well as auxiliary power lift means connected withat least one of said links, the combination of an implement frame having a generally upright portion with means thereon for pivotally connecting the same at vertically spaced points tothe trailing ends of respective ones of the draft links, a pair of ground-engaging elements mounted on said frame for individual movement between raised and lowered positions with reference to said frame, and means operable automatically in response to movement of said upright frame portion relative to the draft links in the course of vertical movement of the latter in raising said frame to transport position for effecting the posi-v tioning of both of said elements in an elevated position with reference to said frame, and also operable as an incident to lowering of said frame by the draft links for coincidentally lowering a selected oneof said elements with reference to said frame while retaining the other element in its elevated position with reference to said frame, said means including a pair of scissor links one of which is pivoted to said frame and the other of which is pivoted to the upper link of said tracton' HAROLD V. HANSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,078,846 Gosnay -Nov. 18, 1913 1,888,502 Holstein Nov. 22, 1932 1,911,218 White -1 May 30,1933 1,972,703 Collins Sept. 4, 1934 2,178,124 Robinson Oct. 31, 1939 2,296,210 Kriegbaum et al. .Sept. 15, 1942 2,312,258 Martin Feb. 23, 1943 2,321,464 Cook June 8, 1943 2,337,801 Cook Dec. 28', 1943 2,352,466 Arps June 27, 1944 2,358,964 Noffsinger Sept. 26,1944 2,376,464 White May 22', 1945 2,401,837 Mellen et al June 11, 1946 2,457,163 Lansing Dec. 28, 1948 i FOREIGN PATENTS "j Number Country Date 473,798 France 1-; Oct. 15, 1914 544,041,

Great Britain Mar. 25, 1942 

